text: // Copyright (c) 2012 The Chromium Authors. All rights reserved.
  // Use of this source code is governed by a BSD-style license that can be
  // found in the LICENSE file.
  
  #include "ui/gfx/ozone/surface_factory_ozone.h"
  #include "ui/gl/gl_bindings.h"
  #include "ui/gl/gl_egl_api_implementation.h"
  #include "ui/gl/gl_gl_api_implementation.h"
  #include "ui/gl/gl_implementation.h"
  #include "ui/gl/gl_implementation_linux.h"
  #include "ui/gl/gl_osmesa_api_implementation.h"
  
  namespace gfx {
  
  namespace {
  
  void GL_BINDING_CALL MarshalClearDepthToClearDepthf(GLclampd depth) {
    glClearDepthf(static_cast<GLclampf>(depth));
  }
  
  void GL_BINDING_CALL MarshalDepthRangeToDepthRangef(GLclampd z_near,
                                                      GLclampd z_far) {
    glDepthRangef(static_cast<GLclampf>(z_near), static_cast<GLclampf>(z_far));
  }
  
  }  // namespace
  
  void GetAllowedGLImplementations(std::vector<GLImplementation>* impls) {
    impls->push_back(kGLImplementationEGLGLES2);
    impls->push_back(kGLImplementationOSMesaGL);
  }
  
  bool InitializeGLBindings(GLImplementation implementation) {
    // Prevent reinitialization with a different implementation. Once the gpu
    // unit tests have initialized with kGLImplementationMock, we don't want to
    // later switch to another GL implementation.
    if (GetGLImplementation() != kGLImplementationNone)
      return true;
  
    switch (implementation) {
      case kGLImplementationOSMesaGL:
        return InitializeGLBindingsOSMesaGL();
      case kGLImplementationEGLGLES2:
        if (!gfx::SurfaceFactoryOzone::GetInstance()->LoadEGLGLES2Bindings())
          return false;
        SetGLImplementation(kGLImplementationEGLGLES2);
        InitializeGLBindingsGL();
        InitializeGLBindingsEGL();
  
        // These two functions take single precision float rather than double
        // precision float parameters in GLES.
        ::gfx::g_driver_gl.fn.glClearDepthFn = MarshalClearDepthToClearDepthf;
        ::gfx::g_driver_gl.fn.glDepthRangeFn = MarshalDepthRangeToDepthRangef;
        break;
      case kGLImplementationMockGL: {
        SetGLGetProcAddressProc(GetMockGLProcAddress);
        SetGLImplementation(kGLImplementationMockGL);
        InitializeGLBindingsGL();
        break;
      }
      default:
        NOTIMPLEMENTED()
            << "Unsupported GL type for Ozone surface implementation";
        return false;
    }
  
    return true;
  }
  
  bool InitializeGLExtensionBindings(GLImplementation implementation,
                                     GLContext* context) {
    switch (implementation) {
      case kGLImplementationOSMesaGL:
        InitializeGLExtensionBindingsGL(context);
        InitializeGLExtensionBindingsOSMESA(context);
        break;
      case kGLImplementationEGLGLES2:
        InitializeGLExtensionBindingsGL(context);
        InitializeGLExtensionBindingsEGL(context);
        break;
      case kGLImplementationMockGL:
        InitializeGLExtensionBindingsGL(context);
        break;
      default:
        return false;
    }
  
    return true;
  }
  
  void InitializeDebugGLBindings() {
  }
  
  void ClearGLBindings() {
    ClearGLBindingsEGL();
    ClearGLBindingsGL();
    SetGLImplementation(kGLImplementationNone);
    UnloadGLNativeLibraries();
  }
  
  bool GetGLWindowSystemBindingInfo(GLWindowSystemBindingInfo* info) {
    switch (GetGLImplementation()) {
      case kGLImplementationEGLGLES2:
        return GetGLWindowSystemBindingInfoEGL(info);
      default:
        return false;
    }
    return false;
  }
  
  }  // namespace gfx
  